Mercurial > hg > beaglert
diff examples/04-Audio/measure-noisefloor/render.cpp @ 464:8fcfbfb32aa0 prerelease
Examples reorder with subdirectories. Added header to each project. Moved Doxygen to bottom of render.cpp.
author | Robert Jack <robert.h.jack@gmail.com> |
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date | Mon, 20 Jun 2016 16:20:38 +0100 |
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children | cdabbaf3a252 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/examples/04-Audio/measure-noisefloor/render.cpp Mon Jun 20 16:20:38 2016 +0100 @@ -0,0 +1,178 @@ +/* + ____ _____ _ _ +| __ )| ____| | / \ +| _ \| _| | | / _ \ +| |_) | |___| |___ / ___ \ +|____/|_____|_____/_/ \_\ + +The platform for ultra-low latency audio and sensor processing + +http://bela.io + +A project of the Augmented Instruments Laboratory within the +Centre for Digital Music at Queen Mary University of London. +http://www.eecs.qmul.ac.uk/~andrewm + +(c) 2016 Augmented Instruments Laboratory: Andrew McPherson, + Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack, + Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved. + +The Bela software is distributed under the GNU Lesser General Public License +(LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt +*/ + + +#include <Bela.h> +#include <cmath> + +int gBufferSize = 8192; + +// Double buffers to hold samples for noise analysis +float *gReadBuffers[10], *gWriteBuffers[10]; +float *gBuffers0[10], *gBuffers1[10]; + +int gWriteBufferPointers[10], gReadBufferPointers[10]; + +// Task to analyse and print results which would otherwise be too slow for render() +AuxiliaryTask gAnalysisTask; + +void analyseResults(); + +// setup() is called once before the audio rendering starts. +// Use it to perform any initialisation and allocation which is dependent +// on the period size or sample rate. +// +// userData holds an opaque pointer to a data structure that was passed +// in from the call to initAudio(). +// +// Return true on success; returning false halts the program. + +bool setup(BelaContext *context, void *userData) +{ + // Clear the filter data structures + for(int i = 0; i < 10; i++) { + gReadBufferPointers[i] = gWriteBufferPointers[i] = 0; + gBuffers0[i] = new float[gBufferSize]; + gBuffers1[i] = new float[gBufferSize]; + gWriteBuffers[i] = gBuffers0[i]; + gReadBuffers[i] = gBuffers1[i]; + if(gBuffers0[i] == 0 || gBuffers1[i] == 0) { + rt_printf("Error allocating buffer %d\n", i); + return false; + } + } + + gAnalysisTask = Bela_createAuxiliaryTask(analyseResults, 50, "bela-analyse-results"); + + return true; +} + +// render() is called regularly at the highest priority by the audio engine. +// Input and output are given from the audio hardware and the other +// ADCs and DACs (if available). If only audio is available, numMatrixFrames +// will be 0. + +void render(BelaContext *context, void *userData) +{ + bool bufferIsFull = false; // Whether at least one buffer has filled + + for(unsigned int n = 0; n < context->audioFrames; n++) { + // Store audio inputs in buffer + for(unsigned int ch = 0; ch < context->audioChannels; ch++) { + if(gWriteBufferPointers[ch] < gBufferSize) { + gWriteBuffers[ch][gWriteBufferPointers[ch]] = + context->audioIn[n * context->audioChannels + ch]; + gWriteBufferPointers[ch]++; + if(gWriteBufferPointers[ch] >= gBufferSize) + bufferIsFull = true; + } + } + } + + if(context->analogChannels != 0) { + for(unsigned int n = 0; n < context->analogFrames; n++) { + // Store analog inputs in buffer, starting at channel 2 + for(unsigned int ch = 0; ch < context->analogChannels; ch++) { + if(gWriteBufferPointers[ch + 2] < gBufferSize) { + gWriteBuffers[ch + 2][gWriteBufferPointers[ch + 2]] = + context->analogIn[n * context->analogChannels + ch]; + gWriteBufferPointers[ch + 2]++; + if(gWriteBufferPointers[ch + 2] >= gBufferSize) + bufferIsFull = true; + } + + // Set all analog outputs to halfway point so they can be more + // easily measured for noise + context->analogOut[n * context->analogChannels + ch] = 0.5; + } + } + } + + + if(bufferIsFull) { + // Swap buffers and reset write pointers + for(int ch = 0; ch < 10; ch++) { + gReadBufferPointers[ch] = gWriteBufferPointers[ch]; + gWriteBufferPointers[ch] = 0; + + if(gReadBuffers[ch] == gBuffers0[ch]) { + gReadBuffers[ch] = gBuffers1[ch]; + gWriteBuffers[ch] = gBuffers0[ch]; + } + else { + gReadBuffers[ch] = gBuffers0[ch]; + gWriteBuffers[ch] = gBuffers1[ch]; + } + } + + Bela_scheduleAuxiliaryTask(gAnalysisTask); + } +} + +void analyseResults() +{ + rt_printf("\e[1;1H\e[2J"); // Command to clear the screen + + // Print the analysis results. channels 0-1 are audio, channels 2-9 are analog + for(int ch = 0; ch < 10; ch++) { + // Skip unused channels + if(gReadBufferPointers[ch] == 0) + continue; + + float mean = 0; + for(int n = 0; n < gReadBufferPointers[ch]; n++) { + mean += gReadBuffers[ch][n]; + } + mean /= (float)gReadBufferPointers[ch]; + + float rms = 0; + for(int n = 0; n < gReadBufferPointers[ch]; n++) { + rms += (gReadBuffers[ch][n] - mean) * (gReadBuffers[ch][n] - mean); + } + rms = sqrtf(rms / (float)gReadBufferPointers[ch]); + + if(ch == 0) + rt_printf("Audio In L: "); + else if(ch == 1) + rt_printf("Audio In R: "); + else + rt_printf("Analog In %d: ", ch - 2); + + rt_printf("Noise %6.1fdB DC offset %6.4f (%6.1fdB) window size: %d\n", + 20.0f * log10f(rms), + mean, + 20.0f * log10f(fabsf(mean)), + gReadBufferPointers[ch]); + } +} + +// cleanup() is called once at the end, after the audio has stopped. +// Release any resources that were allocated in setup(). + +void cleanup(BelaContext *context, void *userData) +{ + for(int i = 0; i < 10; i++) { + delete gBuffers0[i]; + delete gBuffers1[i]; + } +}